Glass.



anion GEORGE A. MAGBETH, F PITTSBURGH, PENNSYLVANIA; GEORGE D. MACBETH,EXECU- TOR OF SAID GEORGE A. MAGBETH, DECEASED, ASSIGNOR TOMACBETH-EVANS GLASS COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATIONOF PENNSYL- Patented Jan. 30, 1917.

VANIA.

GLASS.

1,214 2@2 Specification of Letters Patent.

No Drawing. Application filed April 12, 1915. Serial No. 20,643.

To all whom it may concern:

Be it known that I, GEORGE A. MAoBE'rH, a citizen of theUnited States,residing at Pittsburgh, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inGlass, of which the following is a specification.

The invention relates to an improvement in glass intended primarily foruse in the manufacture of blown illuminating ware such as shades,globes, and the like, al-

" though suitable for use in pressed Ware ment; and the provision of aglass which is cheap, easily worked, without a red or yellow tint, andcapable of withstanding a very high temperature without breaking.

- The foundation batch which I prefer to employ is as follows:

Sand 1000 parts Potash 190 Zinc oxid 240 Borax 66 Salt 5 The foregoingbatch, which aggregates about 1500 parts, if "used without coloringingredients, will produce a substantially colorless clear glass..Various substitutes for the elements might be used to formthis clearglass batch, but the ones given are preferred. f To the foregoing clear1500 parts are added the coloring or opacifying, ingredients comprisingpreferably the following compounds" and quantities 4 Hydrate ofalumiifumfn 190 parts F1uorspa'r 135 Sodium silico fluorid; 150

The clear glass batch with the foregoing coloring compounds arethoroughly'nlixed glass batch of together and melted at a temperature offrom 2.700 F. to 2800 F.

The hydrate of aluminum (Al H O contains 65.4.01) ofoxid of aluminum (A10,) and the percentage of aluminum is 34.6%, so that the 190 parts ofaluminum hydrate hasan aluminum oxid content of 124.2 parts and analuminum content of 65.7 parts. As the aluminun'ioxid is thecoloringagent, other compounds containing the oxid, .such as chinav clay andfeldspar might be used instead of the hydrate, if an adjustment Weremade so as to secure the proper amount of the coloring agent.

The fluorspar (CaF contains 48.7% of fluorin. so that in the 135 partsof fluorspar there is 65.7 parts of fluorin. Other fiuorin compoundsmight be used, such as cryolite, if an adjustment were made to securethe proper amount of fluorin.

The sodium silico fluorid (Na SiF contains 60.6% of fluorin so that inthe 150 parts of this compound there are 90.9 parts of fluorin. Someother fiuorid might possibly be substituted for thesodium silico fluoridif an adjustment were made to secure the proper amount of fluorin. Thetotal fluorin content in the fluorspar and sodium silico fluorid is 65.7parts plus 90.9 parts or 156.6 parts. I,

It will be understood that, aside from the substitution of equivalentcompounds for those above indicated, the proportions of the elementsmight be modified to a considerable extent and still producesubstantially the same glass as that produced when the exact formula asabove set forth,'is employed; For instance, the aluminum oXid contentmay be varied between and 160 parts, the fluorspar between 100 'and 170parts, and the sodium silico fluorid between l00.and 200 parts. Theformula and pro portionsns above set forth, are, however,

- the ones which are preferred by me and which have produced the glasshaving the qualities" referred toiand also stated later.

The glass as produced fromthe foregoing formula will stand a-very hightemperature without breaking, such quality being particularlyadvantageous when the'glass 'is used in connection with high powernitrogen and gas lamps giving-out an intense heat. The glass is alsodesirable with such' high power illuminating elements since it diffusesthe light without permitting the lighting element to 'be seen, and thisis the case even with a relatively thin blown shade or globe. At thesame time, the glass permits of the passage of a large ercentage of thelight so that a proper i1 umination is secured by the transmitted light,such as could not be secured with the relatively dense milk-glassesheretofore known in the prior art. In appearance, 'the' glass is whiteand luminous and without the objectionable yellow or brown tingecharacteristic of opal glasses. The glass furthermore, is very easilyworked and relatively cheap.-

What I claim is:

1. A glass formed by fusing together a mixture containing approximatelythe 01 lowing proportions; 1500 parts of founcla tion batch capable ofmaking substantiallyv clear glass, 124 parts of aluminum oxid,

135 parts of fluorspar and 150 parts of sodium silico fluorid. v

2. A glass formed by'fusing together a mixture containing approximatelythe following proportions, 1500 parts of foundation batch capable ofmaking substantially I, clear glass, 124 parts of aluminum oxid, 135

parts of a fluorid containing about by weight of fluorin and 150 ofsodium silico fluorid. e

3. A glass formed by fusing together a mixture comprising 1500 parts ofa foundation batch capable of making substantially clear glass, to 160parts of aluminum oxid, to 170 parts of a fluorid containing about 50%by weight ,of fluorin, and

100 to 200 parts of sodium silico fluorid. 4JA glass rmed y fusingtogether a 1,214,aoa

mixture comprising 1500 parts of a foundation batch capable of makingsubstantially 'clear glass, 80 to parts of aluminum oxid, 100 to 17 0parts of a fluorid containing about 50% by weight of fluorin, and 100 to200 pa of a second fluorid.

521A- glass formed by fusing together a mixture comprising 1500 partsofa foundation batch capable of making substantially clear glassandincluding zinc oxid, 80 to 160 parts of aluminum oxidg 100 to partsof a fluorid containing about 50% by weight of fluorin, and 100 to 200parts of sodium silico fluorid.

6. A glass mixture comprising tion mixture capable of makingsubstantially clear glass, with compounds containing from 40 to 90 partsof aluminum and formed by fusing together a 1500 parts of a founda- 110to 200 parts offluorin, one of said compounds'being sodium silicofluorid.

7. A glass formed by fusing together a mixture comprising 1500 parts ofa fbundation mixture capable of making substan tially clear glass, andincluding'zinc oxid, with compounds containing from 40 to 90 (parts ofaluminum 'and 110 to 200 parts 8'. A glass formed -by fusing together a.

mixture comprising 1500 parts of a foundation mixture capable of makingsubstan-' tiall clear glass, with compounds containing rom.40 to 90parts of aluminum and 110 to 200 parts of fluorin, one of s'aidcompounds being sodium silico fluorid and an- MAQBETH';

